Homeowners

Ask the Inspector

Fences Can Be a Chip Off the Old Block

I'd like to put a block wall around my property. Do I need a permit for this?

In the City of San Diego, fences -- including those made from masonry -- don't need a permit in most cases if they're no taller than six feet high. Zoning approval may be needed in some areas, however; call (619) 446-5000 to check before you build.

Although a construction permit and inspection isn't required, the City does have publications -- and they're free -- with specifications for construction of fences made from wood or block. (Remember, we're talking about a fence made from masonry, not a retaining wall. Retaining walls -- a wall has a slope behind it, for example -- in many cases do require permit and have different requirements.)

Our Information Bulletin 223 (PDF) shows construction specifications for block walls. Its a good guide for the consumer; whether you're installing it yourself or hiring someone, it gives you specifications for a minimum level of safety and performance.

The considerable weight of a block wall means some care should be taken in construction. During recent earthquakes, many block fences severely cracked or toppled, leading to injuries and property damage. In some cases, this was due to minimal construction.

A wall may look solid when you finish it, but over time grout -- the material holding the blocks together -- can weaken. Care and a little extra money in construction can result in a more substantial wall that will last longer.

Our Information Bulletin includes specifications for footings' concrete, mortar and grout mixes. You don't just dump some cement, sand and gravel in a bucket and start mixing. If the proper proportions aren't used, the concrete, mortar and grout might not be strong enough to withstand the stress of wind, earthquakes, or your daughter playing tennis off the wall.

Steel is also a must. If properly located and anchored, the steel gives the wall vertical strength. It also needs to be properly anchored in the footing of the wall... just sticking it in the holes isn't enough.

A masonry fence is also a very heavy thing. Make sure the soil underneath it is solid and level. Drainage ditches, soft or loose soil can all contribute to failure.

Again, a permit isn't needed in most cases for a masonry fence. This puts all the responsibility on you, the home owner. Cutting corners today might mean that a few years down the road you'll have to replace that solid looking masonry fence.

Do it right the first time... you'll save in the long run.

As always, if you live outside of the City of San Diego, check with your local jurisdiction before building.